The city-states were founded as part of the southward migration by the Tibeto-Burman-speaking Pyu people, the earliest inhabitants of Burma of whom records are extant.

Five major walled cities- Beikthano, Maingmaw, Binnaka, Hanlin, and Sri Ksetra- and several smaller towns have been excavated throughout the Irrawaddy River basin.

[4] Based on limited archaeological evidence, it is inferred that the earliest cultures existed in Burma as early as 11,000 BCE, mainly in the central dry zone close to the Irrawaddy.

[8] Archaeological evidence at Samon River Valley south of Mandalay suggests rice-growing settlements that traded with China between 500 BCE and 200 CE.

[2][11] The Pyu realm was longer than wide, stretching from Sri Ksetra in the south to Halin in the north, Binnaka and Maingmaw to the east and probably Ayadawkye to the west.

According to Stargardt in “From the Iron Age to early cities at Srikestra and Beikthano, Myanmar” Journal of Southeast Asian Studies, all the archaeology found a lot of major inscriptions on stone in phy language survive at Sri Kestra (Pyu), Hanlin and near Pinle (Hmainmaw), and Pagan (Bagan).

As Stargardt acknowledges in that article, "Sri Kestra" contained fields, irrigation canals, water tanks and iron-working sites, as well as monuments, markets (and elusive habitation areas) both inside and outside walls, all these halls also provide evidence of a powerful belief system in the elaborate provision of the dead”.

[13] Archaeological surveys have actually so far unearthed 12 walled cities, including five large walled cities, and several smaller non-fortified settlements, located at or near the three most important irrigated regions of precolonial Burma: the Mu River Valley in the north, the Kyaukse plains in centre, and the Minbu region in the south and west of the former two.

[14] The city-states were contemporaries of the Kingdom of Funan (Cambodia) and (perhaps) Champa (southern Vietnam), Dvaravati (Thailand), Tambralinga and Takuapa near the Kra Isthmus, and Srivijaya (southeast Sumatra).

[15] It was a long-lasting civilisation that lasted nearly a millennium to the early 9th century until a new group of "swift horsemen" from the north, the (Mranma) (Burmans) of the Nanzhao Kingdom entered the upper Irrawaddy valley through a series of raids.

[4] Of the 12 walled cities excavated thus far, five are the remains of largest Pyu states: Beikthano, Maingmaw, Binnaka, Halin and Sri Ksetra.

The plan of a circle within a square suggest a zodiac sign which represents a view of the heavens from the perspective of the sun, the manner in which 19th century Mandalay was also conceptualised.

[14] Halin or Halingyi (ဟန်လင်းကြီး [həlɪ́ɰ̃dʑí]), located in the Mu valley, one of the largest irrigated regions of precolonial Burma, is the northernmost Pyu city so far discovered.

[25] Known for the production of salt, a highly prized commodity in the first millennium, Halin was superseded by Sri Ksetra as the premier Pyu city-state circa 7th century.

The city's brick walls were 4.5 metres (15 ft) high, and had 12 gates with huge devas (deities) guarding the entrances and a pagoda at each of the four corners.

Based on its scale and the administrative societal structures of the Pyu period, the city would have been built by a monarch, rather than a feudal lord.

Its absence in the Bagan Kingdom's fourth period records also indicates that the city likely fell into ruin well before the 11th century AD.

[29] Further south in Myingyan Township, west of Maingmaw, the Wati site (also spelled Wa Tee) is the remnants of a circular walled city.

[37] There were also Pyu settlements in Lower Burma that may have been ignored or overlooked by the historical records aimed at legitimizing Upper Burmese kings' lineage.

All important Pyu settlements were located in the three main irrigated regions of Upper Burma, centred on the confluence of the Irrawaddy and Chindwin rivers: Halin in the Mu valley, Maingmaw and Binnaka in the Kyaukse plains, finally Beikthano and Sri Ksetra at or near the Minbu district.

King Anawrahta of Pagan would build irrigation projects in these three regions in the 1050s to turn them into the main rice granaries of Upper Burma.

[41] Likewise, Pyu artefacts have been found along the coasts of Arakan, Lower Burma, and as far east as Óc Eo (in present-day southern Vietnam).

Avalokiteśvara (Lokanatha) (called Lawkanat in Burmese; လောကနတ် [lɔ́ka̰ naʔ]), Tara, Manusi Buddhas, Vaiśravaṇa, and Hayagriva, all prominent in Mahayana Buddhism, were very much part of Pyu (and later the Pagan) iconography scene.

[48] Though their religious beliefs was a syncretic mix of many backgrounds, probably like in the early Pagan period, the outlook of the Pyu reportedly was largely peaceful.

The Chinese records state that the 35 musicians that accompanied the Pyu embassy to the Tang court in 800–802 played music and sang in the Fan (Sanskrit) language.

It is believed that circular patterns inside the cities were Pyu while the rectangle or square shape of the outer walls and the use of 12 gates were Indian in origin.

The styles, ground plans, even the brick size and construction techniques of these buildings point to the Andhra region, particularly Amaravati and Nagarjunakonda in present-day southeastern India.

The solid stupas of Sri Ksetra were in turn prototypes for Pagan's such as the Shwezigon, Shwehsandaw, and Mingalazedi, and ultimately, the Shwedagon in modern Yangon.

[53] The city-states were mainly populated by the Tibeto-Burman-speaking Pyu people, who like their cousins Burmans are believed to have migrated from the present Qinghai and Gansu provinces in north-central China, via Yunnan.

The chiefs at larger city-states later styled themselves as kings, and established courts largely modelled after the Indian (Hindu) concepts of monarchy.